Heater



D. K. DEAN HEATER 2 Sheets-Sheet l Filed Dec. l0, 1945 /O/v A. D54

ATTORNEY D. K. DAN

HEATER Filed Dec. 10, 1945 2 Sheets-Sheet 2 lNvENToR .D/o/v K D5/mf,

v ATTORNEY Patented Dec. 23, 1947 HEATER Dion K. Dean, Rahway, N. J., assigner to Foster Wheeler Corporation, New York, N. Y., a corporation of New York Application December 10, 1943, Serial No. 513,791

13 Claims.

This invention relates to heating systems and more particularly to the control of temperature in vapor heating systems.

The invention provides a novel vapor heating system in which the temperature of a substance heated by a condensible vapor is automatically controlled by the use of a regulated quantity of non-condensible vapor.

The invention will be understood from the following description when considered in connection with the accompanying drawings forming a part thereof and in which:

Fig. 1 is a diagrammatic View of a closed vapor heating system of the present invention having a single heat user;

Fig. 2 is a View similar to Fig. 1 but showing a closed vapor heating system having a plurality of heat users;

Fig. 3 is a sectional view showing one manner of connecting a heat user into the heating system, and

Fig. 4 is a sectional View of a pressure compensating valve used in the heating system of the present invention.

Like characters of reference refer to like parts throughout the views.

Referring to the drawings, the reference numeral I designates the setting of a vapor generator for generating a condensible vapor from a high boiling point liquid such as diphenyl, diphenyl oxide or an equivalent high boiling point liquid. The generator has an upper drum I I and a lower drum I2 connected by a main bank of vapor generating tubes I3. A combustion chamber Hl red by burner l5 is positioned at one side of the tube bank, the products of combustion from which are directed over the tube bank by baies and thereafter pass into a iiue at the opposite side of the bank I3. The walls of the chamber are lined by tubes l5 which are connected into the circulatory system of the generator. It will be understood that other types of vapor generators may be used if so desired. The drum Il of the vapor generator is connected, as shown in Figs- 1 and 2, to the top of a heat user Il by means of a condensible vapor conduit I8. The flow of vapor through the conduit i8 is controlled adjacent the drum Ii by a valve I9 iid adjacent the user il by means of the valve The heat user Il', as shown, is in the 'form of a container and has a chamber 2l adapted to receive a substance to be heated. The wall 22 of the heat user il is surrounded by a vapor jacket 23 which jacket is in communication with the condensible vapor conduit I8. The inner surface of the wall 22 of user il constitutes the heating surface by means of which. the substance in the chamber 2ir is heated. A vapor outlet connection 24 is in communication with the sufficiently high above the vapor generator,

gravity may be depended upon for the return of condensation to the vapor generator. Should the elevation of the user not be suiiiciently high, a return pump 25 is used. The suction side of the pump 26 is connected to the conduit 25 by means of a pipe 21, while the discharge side of the pump is connected to the conduit 25 by means of conduit 28. The pump 26 may be connected into or disconnected from the conduit 25 by means of a valve 29 in the conduit 25 at a point between the point of connection of the conduits 2l and 28 to the conduit 25 and also by means of a valve 3B in the conduit 2l.

The temperature to which the substance in the chamber 2|, of the user II is heated is regulated by the introduction of non-condensible vapor into and the withdrawal of non-condensible vapor from the jacket 23 of the user I'I. The greater the amount of non-condensible vapor in the jacket 23 the lesser the degree to which the inner surface of the wall V22 is heated and conversely, the lesser the amount of non-condensible vapor in the jacket 23 the higher the degree to which the inner surface of the wall 22 is heated. In order to introduce or withdraw non-condensible Vapor from the jacket 23 and thereby control the temperature to which the substance in the chamber 2| of the user I 1 is heated, a conduit 3l is connected at one end to the discharge outlet 24 at a point intermediate the point at which the outlet connection 24 is connected to the jacket 23 and the point at which the conduit 25 is connected to the outlet connection. The opposite end of conduit 3l is connected to a conduit 32 which is in communication at one end with a suction chamber 33. The conduit 32 is controlled at a point between the suction chamber and thepoint at which conduit 3l is connected thereto by a solenoid valve 34 which valve is adjusted to be opened against the tensio-n of a spring 35 when the solenoid 36 is energized and to be closed by the tension of the spring when the solenoid is de-energized. The suction chamber 's3 is in communication with the suction side of a pump 31 through a conduit 33. rhe pump 3! is preferably of the centrifugal hydraulic type which is sealed with liquid similar to that used in the vapor generator and is adapted to compress non-condensible vapo-rs received from the user I l' through the conduit 3l, suction chamber 33 and conduit 38 and pass the same through adischarge conduit 39 densing coil 4Q through which a cool fluid flows. A return conduit 4| controlled by a regulator valve 42 isy connected at one end to the bottom of the container 4i! and at the other end to the conduit 33 so that suiiicient sealing liquid will bey returned to the compresso-r 31 to assure continuous operation thereof. Conduit 32 also is in communication with the top of the receiver 4i) and receives non-condensible vapors from. said receiver. The conduit 32 is controlledY by a solenoid valve 53 at a point between the connection of said conduit to the receiver and the point of connection of the conduit 3| to the conduit 32. The valve 43 is adapted to be opened against the tension of the spring 44 when the solenoid 45 is energized and to be closed by the tension of said spring when the solenoid is de-energized. The container lll). is provided with a float valve 46 which prevents the liquid in theY container 4|! from rising above a predetermined level. The valve 86 controls an outlet which is in communication with the condensate return conduit 25 through a pipe l1 so that when the liquid in the container 45 rises above a predetermined level, the valve i8 will be opened andthe excess liquid will flow through the line d1 into the condensate return line 25 thence into the vapor generator.

In order to regulate the temperature to which the substance in the chamber 2| of the heat user I1 is heated. a thermostatic control which governs the flow of non-condensiblel vapors into the jacket 23. and also governs; the withdrawal of nonconclensible vapor from the jacket byv controlling the operation of the valves 34 and 43, is provided. The thermostatic control comprises a bulb 48 inserted in. the chamber 2| in such a position that it will be contacted by a substance in said chamber. The bulb 438 is connected by capillary tubing 49' to a Bourdon tube 58 which tube is responsive to any rise or fall of temperature in the chamber 2|. A movable contact arm 5| is connected to the Bourdon tube 0 and is actuated into and out oi contact with adjacentlyI disposed fixed contacts 563 and 55 by said tube. The contact arm 5 is in electrical connection through lines 52 and 53 with pole A of an electrical source. The fixed co-ntacts 5G, and 55are positioned at opposite sides of the arm 5|' and normally are in spaced relationship thereto. The contacts are adjustable so that the space, between either of them and the moyable contact may be varied as desired. Fixed contact 55 is in electrical connection with the coil 550i a solenoid switch 51 through a line 58. Coil 56' is electrically connected through lines 59 and |58 to the, pole B of the electrical source. One of the fixed contacts 8| of the solenoidV switch 51 is connected tothe line 53 by the lines 62 and 63 while the other iixed contact 54 is connected to the solenoid 35 of the solenoid valve-34 by means or the line 65. The solenoid 36 isV also electrically connected to the line 6G by means of the line 66.

The fixed contacty 54v is connected to the adjustable iixed contact 814 of' a fluid pressure responsive switch 88 through a line 69. The fluid pressure responsive switch 58 comprises a movable contact arm lli adapted to be moved into and out of engagement with xed contacts 61 and 1| by the action of bellows 12 and 13. The operation of the switch 88 will hereinafter be fully setforth. Normally, however, the contact arm will be in engagement with the fixed' contacts 81 and 1|. The xed contact Tl of the switch 68 is connected to a coil of a solenoid switch 15 by the line 16. The coil 'lll is also connected to the line 60 through the line 11. The-iixed' Contact '|8'0f the 4 switch 15 is connected to the line 53 through the ine 63 while the other xed contact 19 is in electrical connection with the. coil 45 of the solenoid valve 33 through the line 8l). The coil 85 is also connected to the line 60 through the lines 8| and 65.

In order that an amount of non-condensible vapor in excess of the capacity of jacket 23 will not be delivered to the jacket and iiow back into the vapor generator through the conduit I3, an automatic control is provided which control is adapted to actuate the switch 68 and break an electrical circuit to the valve t3 so that the valve will close and prevent further flow of non-condensible vapor from the container 40 to the jacket when the capacity thereof' is reached. This control comprises a pressure drop or tell-tale device 82 which, as shown in Figs. l and 2, is connected to the heat user l1l adjacent the top and to the side thereof opposite that to which the condensible vapor conduit |8 is connected. The tell-tale device 82 has a chamber 83 therein which is in communication through a port Silv with the jacket 23. An inlet orifice plate is positioned in the chamber 83 adjacent port 84, the inlet orifice plate 85 having an orifice therein of a lesser diameter than that of the port 8d. Adjacent the opposite end of the chamber 83 of the device 82, is an outlet orice plate 88 similar to the plate 85. The body of the device 82 is provided on the outside thereof with condensing means which extends between the twok orifice plates and, as shown, comprise a plurality of radiating ns 81 each of which extends circumferentially of the device in spaced relationship with one another. Device 82 is connected at the end thereof adjacent the orice plate 8B to the suction chamber 33 by means of the conduit 88. Vapors are drawn from the jacket 23 through the port 84, aperture plate 85, chamber 83 and aperture plate 86, conduit 88, suction chamber 33 and conduit 38 by the pump 31. During normal operation of the system, a small amount of the condensible vapor in the jacket 23 is drawn through the tell-tale device. A large portion of this vapor is condensed in the chamber 83 thereof, the condensate passing into the jacket 23 through the loop seal 89. Consequently, only a small portion of the condensible vapors will remain to flow through the orifice plate 86 which results in a small pressure difference between the upstream and downstream sides of the plate 86. When the jacket 23 becomes iilled with noncondensible vapor and the same, together with a small amount of condensible vapor, is drawn through the tell-tale device, since none of the noncondensible vapor will be condensed in the chamber 83, there will be a greater pressure drop between the upstream and downstream sides of the plate 38 than when condensible vapor alone is drawn through the device. The pressure responsive switch 88 is adapted to be actuated by the pressure drop across the plate 86, the bellows 13 of said switch being in communication with the device 82 on the downstream side of the plate through the tube 9|) while the bellows 12 is in communication with the chamber 83 on the upstream side of the orifice plate 86 through the tube 9|. Increased pressure in the chamber 83 on the upstream side of the plate 86 when non-condensible vapor is drawn through the tell-tale device causes the bellows 12 of the switch 88 to expand moving the arm 10 to the left of Figs. l and 2, against the smaller amount of pressure in the bellows 13, and out of contact with the xed contacts 61 and Hl breaking the circuit to the valve 43- causing the same to close and thereby prevent further non-condensible vapor from passing into the jacket 23, as will hereinafter be fully described.

A differential pressure control valve 92, which is shown in detail in Fig. 4, is positioned in the line 88 and operates to maintain a constant difference in pressure between the section of the line 88 extending from the device 82 to the valve 92 and the pressure in the jacket 23. The valve 92 comprises oppositely disposed bellows 93 and 94, the bellows 93 engaging kone end of a valve stem 95 having a valve 96 attached thereto which valve is adapted to be seated on seats S'I while the bellows 94 is adapted to engage the opposite end of the valve stem. Thebellows 93 is in communication with the jacket 23 through the conduit 95 while the bellows 9|! is in communication with the line 88 at a point between the valve 92 and the outlet end of the device 82 through a conduit 96'. An adjustment is provided for compensating for the diiierence in pressure between the pressure within the bellows 93 and the pressure within the bellows gli so that the valve 9e will be moved toward its open position when the pressure in the bellows 94 increases beyond a predetermined amount in relation to the pressure in the bellows 93 and will be moved toward its closed position when the pressure in the bellows 93 increases beyond a predetermined amount in relation to the pressure in the bellows t4. This adjustment comprises an adjusting nut |22, which cooperates with threads on the valve stern 25, and a spring i23 which acts upon the nut and a xed plate |24 having an aperture of greater diameter than the valve stem and through which the valve stem extends. Normally, as determined by adjustment of the adjusting nut |22, the valve 9E is unseated sufliciently to permit vapor to iiow through the line 88. Should the pressure in the jacket 23 increase with respect to the balancing pressure in the tubes 38 and 95', the pressure in the bellows 93 will increase relatively tc that in the bellows 94 which causes the valve 96 to move toward a closed position thereby decreasing or stopping the flow of vapor through the line 83 which causes pressure to build up in the line |38 between the valve 92 and the outlet of the device 82. The pressure will increase in the lines 93, 99 and bellows 94 until the pressure therein counterbalances the pressure in the bellows 33. As the pressure in the bellows Si. is increased, the valve 96 is returned toward its normal open position. Should the pressure in the line 88 between the valve 92 and the device 82 increase above that in the line 95 the increased pressure is conveyed through the line 95 to the bellows fifi which causes the bellows to expand. Since the pressure in the bellows 94 will increase relatively to the pressure in the bellows 93, the valve stern will be moved in a direction which causes the valve 92 to be moved away from the seat 9i thereby permitting a greater iiow of vapor through the line 89 and decreases the pressure therein. As the pressure in the lines 8S and 9 decreases, the pressure in the bellows 94 decreases which causes the valve 9S to move toward its closed position. When the pressure in the bellows S3 and the pressure in the bellows 94 counterbalance the valve @ii will be in its normal position.

It is necessari7 to insure a suiiicient amount of non-condensible gases always being available in the container e0. To insure an adequate supply of said gases, a non-condensible vapor container |00 is in communication with the container iii through a conduit IOI which is connected to said Asubstance in the chamber 2|.

container above the normal level of liquid therein. The iiow of gases from the container |00 into the container 20 is controlled by the normally closed solenoid valve |02 in the conduit IOI. To control the opening and closing of the valve |02, a diiTerential pressure control valve I 63 is used which valve comprises opposed bellows |04 and |05 and a movable contact arm |06 positioned intermediate the bellows. Bellows |05 is in communication with the upper part of the container 40 through a conduit -II'i'I while bellows |03 is in communication with the condensible vapor line I8 through the conduit |08. The contact arm It is normally out of engagement with the Xed contacts I 09 and II 0. The fixed contact |99 is connected to the coil of the solenoid switch I I2 through the line I I 3. The coil I I is also connected to line 53 through line I III. Fixed contact H9 of the switch |63 is connected to the line B0 through the lineI I5. The iixed contact II 6 of the solenoid switch II2 is connected to the line 53 through the line I I'I while the other xed contact |I8 is in electrical connection with the coil |I9 of the solenoid valve |02 through line |20, the coil IIB being connected to the line 60 through the line I2 I.

In operation, condensible vapor is generated in the vapor generator by passage of the gases of combustion from the burner I5 in heat exch-ange relationship with the bank of vapor generating tubes I3 and the tubes |6. Vapor passes from .the drum II into the jacket 23 of the heat user I1 through the open Valve I9, condensible vapor conduit I8, and open valve 20 to thereby heatthe When the substance in the chamber 2| is heated above a, predetermined temperature, as determined by the thermostatic bulb 48, the Bourdon tube 50 is actuated by heat transmitted thereo through Athe capillary tubing 4S to move the contact arm 5| into engagement with the Xed contact 54. Electric current will then flow from the pole A through lines 53 and 52 into contact arm 5|, thence through the iiXed contact 54, line B9, into fixed contact 6l, movable contact 10, and fixed contact 'II of the switch 68 and then into the coil 'I4 of the switch 'I5 through the line 7B. Coil 'I4 will thereby become energized since the coil also is in electrical connection with the pole B through the lines 'I'I and 60. Energizingof the coil 'I4 will cause the movable contact of the switch 'I5 to be brought into engagement with the fixed contacts 'I8 and 'I9 of said switch which will permit electric current to ow from the line 53 through the line 63, xed contact '18, movable contact 'I5' and Xed contact 'I9 of the switch 15, thence through the line 80 into the coil 45 of the solenoid valve 43 which energizes the same because said coil is in connection also with the line 69 through the lines 8| and 66. Energizing of the coil 45 causes the valve 43 to be opened against the tension of the spring 44 permitting non-condensible Vapor to flow from the container 40 through the conduit 32 into the conduit 3| thence, into the jacket 23 of the heat user through conduit 3| and outlet connection 24. The non-condensible vapor thus flowing into the jacket 23 tends to blanket the wall 22 of thetheat user I'I against contact with the condensible vapor flowing into the jacket through the conduit 8. The degree to which the wall 22 is heated is thereby reduced which in turn reduces the degree to which the substance in the chamber 2| is heated. The greater the amount of non-condensible vapor in the jacket 23 the lesser the degree to which the substance in the chamber 2| is heated. The thermostatic bulb 48 causes the Bourdon tube 50'to be actuated to break the connection between the movable contact and the xed contact 54 when the temperature to which the substance in the chamber 2| of the heat user |1 is heated is decreased to a predetermined degree. The coil 14 of the solenoid switch 15 is deenergized, when the contacts 5| and 54 are disengaged, permitting the spring in said switch to move the movable contact out of engagement with the fixed contacts 18 and 19. Disengagement of the movable arm of the switch 15 from the contacts 18 and 19 breaks the electrical circuit to the coil 45 of the solenoid valve 43 causing said valve to be closed by the action of the spring 44. Flow of non-condensible vapor from the container lll) through the conduits 52 and 3| and into the jacket 23 of the user is thereby stopped. Should the degree to which the substance in the chamber 2| of the user |1 is heated decrease below a predetermined degree, the thermostatic bulb 48 will cause the Bourdon tube 56 to move the movable contact 5| into engagement with the xed contact 55 which permits current .to flow from the pole A through lines 53 and 52, movable contact 5|, xed contact 55 and line 58 into the coil 56 of the solenoid switch 51 thereby energizing the coil because said coil is connected to the pole B through the lines 59 and 65. Energizing of the coil 55 causes the movable arm of the switch 51 to move into engagement with the fixed contacts 6 l' and 64 thereby closing said switch. Current will then flow from the line 53 into the lines 63 and 62, into .the xed contact 6|, through the movable arm of the switch 51 into the iixed contact 64, through the line 65 and into the coil 36 of .the solenoid valve 34 in conduit 32. Since the coil 36 is connected t0 the line 68 through the line 66, it becomes energized, thereby opening the solenoid valve 34 against the tension of the spring 35, Opening of the solenoid valve 34, permits non-condensible vapor yto be withdrawn from the jacket 23 by the pump 31, which is operated continuously, the noncondensible vapor being withdrawn through conduits 3| and 32, suction box 33 and conduit 38 by said pump and thence discharged into the container 40 through the conduit 39l Any condensible vapor withdrawn from the jacket 23 with the non-condensible vapor is discharged into the container 48 and is condensed by cooling coil 46. When the condensate rises above a predetermined level in the receiver, the valve 46 is opened permitting the excess condensate to flow through the conduit 41 into the return conduit 25 and thence into the drum I2 of the vapor generator. Conden-sate formed from the condensible vapor in the jacket 23 flows through the conduit 25 into the drum |2 of the vapor generator as hereinbeiore set forth.

Withdrawal of non-condensible vapor from the jacket 23 reduces the amount of non-condensible vapor in the jacket, decreasing the areaof the wall 22 blanketed by the non-condensible vapor` and providing a greater space in the jacket for condensible vapor. The greater the amount of condensible vapor in the jacket 23, the greater the area of the wall 22 which will be contacted by the condensible vapor and the higher the temperature to which the Wall 22 and the substance in the chamber 2| will be heated. The thermostatic bulb 48 will cause the movable contact arm 5| of the Bourdon tube 50 to disengage the xed contact 55 when the temperature of the substance in the chamber 2| is raised above a predetermined temperature,

Under normal operating conditions, the jacket 23 is substantially entirely filled with condensible vapors. A small amount 0f these vapors will ow into the tell-tale device 82 through the port 84 and orice plate at a continuous rate. A large portion of such vapors passing into the device 82 will be condensed in the chamber 83 of the device between the orice plates 85 and 86, the condensate passing from the chamber 83 through the loop seal 89 into the jacket 23. A small portion of the condensible vapors will remain uncondensed and flow through orifice plate 86 thence out of the tell-tale device and into the conduit 88. This results in a small pressure difference between the upstream and downstream sides of the orifice plate 88. Under such conditions, the pressure responsive switch 68 is closed', the movable arm 15 thereof being in contact with the xed contacts 61 and 1|. Also, the valve 92 is in its normal open position, that is, the valve is positioned off the seat 91 suiciently to permit a normal amount of condensible vapor to pass through said valve. Should the movable contact 5| of Bourdon tube 5i! remain in engagement with the fixed contact 54 after the jacket 23 is filled with non-condensible vapor, the vapor will continue to flow into said jacket thereby providing an excess of noncondensible vapor which will flow through the port 85, orice plate 85 and into the chamber 83 of the tell-tale device 82. The amount of condensible vapor passing into the chamber 83 will decrease and the amount of non-condensible vapor will increase so long as contacts 5| and 52 remain in engagement. Since none of the noncondensible vapor passing through the oriiice 85 will be condensed in the chamber 83 the volume of vapors passing through the orifice plate 85 into the line 88 will increase. This will cause a greater pressure drop across the oriiice plate 86 than would be the case if only condensible vapor was passing from the jacket into the tell-tale device. 'Ihe pressure on the upstream side of the plate is, therefore, increased. Increased pressure on the upstream side of the oriiice plate 86 will cause the pressure in the tube 9| to be increased over that in the tube 50. The increased pressure in the tube 9| will increase the pressure in the bellows 12 over the pressure in the bellows 13 causing the bellows 12 to expand and thereby move the arm 10 to the left of Figs. l and 2 and out of engagement with the contacts 61 and 1|. Disengagement of the movable contact 1S from the xed contacts 61 and 1| causes the coil 14 of the solenoid switch 15 to become de-energized causing the movable contact of the switch to move out of engagement with the xed contacts 13 and 19 thereby breaking the electrical circuit to the coil 45 of the solenoid valve 43, causing said valve to be closed by action of the spring 44. Closing of the Valve 43 prevents further low of noncondensible vapor from the container i to the jacket 23 of the user |1.

When the amount of non-condensible vapor in the container 40 falls below the desired quantity, the pressure within the container decreases which in turn causes the pressure in the conduit |01 and bellows |05 of the switch |83 to become lower. Lower pressure in the bellows |65 will cause the higher pressure in the bellows |65 to move the contact arm |06 into engagement with iixed contacts |69 and ||8 of the switch |53 closing said switch. Closing of the switch |63 permits electric current to ow from the lines 53 and H4 into the coil of the switch ||2 and from the lines B and l5 through the contacts I8, |06, |09

and line II3 into the coil III thereby energizing said coil. Energizing of the coil II closes the switch I I2 by moving the movable contact of said switch into engagement with the Xed contacts IIG and IIB. Current will then iiow into coil IIS through the lines 53 and II'I, switch II2 and line I2ll, and also through lines Gli and IQI thereby energizing said coil and opening the valve it against spring tension. Non-condensible vapor from the non-condensible vapor container le@ then iiows into the receiver 40 through the conduit lill. When a suiicient amount of non-condensible vapor is introduced into the container lill, the pressure in said container, tube Iil'i and the bellows IUS will be slightly greater than that in the bellows 04 and suicient to move the movable contact lG of the switch Illa out of engage ment with the fixed contacts 39 and Ii@ thereby breaking the electrical circuit to the coil lil of the switch H2 causing the switch to become opened. Opening of the switch IIZ, breaks the electric circuit to the coil I I9 of the valve H32, deenergizing the coil I I9. This causes the valve H12 to be closed by the tension of the spring thereof preventing further ow of non-condensible vapor from the non-condensible container lil!) into the container dil.

A heating system similar to that shown in Fig. l is illustrated in Fig. 2. The system of Fig. 2, however, has more than one heat user Il the heating of each of which is controlled independently of the other by apparatus similar to that in the form of the invention shown in Fig. 1. The condensible vapor conduit I8 is extended to communicate with the packet 23 of a second heat user Il while the condensate return conduit 25 is in communication with the outlet connection 2i' of the heat user Il through the conduit 25. The suction conduit 88 is extended to communicate with the tell-tale device 82 on the user I7'. Non-condensible vapor is introduced into the jacket 23 of the user I'I through the conduit 32 and the conduit 3l. The conduit 32 is connected at one end to the conduit 32 at a point between the container 4i! andthe valve 43 of the control apparatus for the user I I and is connected at the opposite end to the suction line 88. Flow of noncondensible vapor into the packet 23 of user Ii" is controlled by the valve 43' in the conduit '32 while now of non-condensible vapor from the jacket 23 into the container lill is controlled by the valve 3Q in the conduit 32. The flow of the non-condensible vapor is controlled by said valves in the same manner as in the form of the invention shown in Fig. 1. With the arrangement of apparatus shown in Fig. 2, both of the heat users VI and I'Il are under constant vapor pressure from the vapor generator through the line I8. The heat absorbing capacity of the users Il and Il may be varied independently of one another by separately controlling the amount of noncondensible Vapor introduced into each without varying the pressure. The pressure is, therefor, maintained constant in a plurality of heat users while the heat absorbing capacity of any user may be varied independently of other heat users.

The tell-tale device 82 in the form of the invention shown in Fig, 3 is connected to the vapor outlet connection 24 at the bottom of -the heat user Il. Conduit 3|, through which non-condensible vapor is introduced into and withdrawn from the jacket 23 of the heat user I'I, is connected to the top of the user I1 while the conduit I8 through which condensible vapor enters the jacket 23 is connected to the connection 24. The

tell-tale device is in communication with the connection 24 at a point between the bottom of the jacket 23 and the point of connection of the conduit I8. After the jacket 23 becomes filled with non-condensible vapor and the flow of vapor to said jacket continues, the excess non-condensible vapor flows through said tell-tale device causing the same to operate the apparatus controlling the flow of non-condensible vapor to the jacket in the same manner as in the form of invention shown in Figs. 1 and 2.

The term non-condensible vapor as used in the specification and the term non-condensible gas as used in the claims includes a vapor or gas which will not condense in the heat user of the present invention.

Since variations may be made in the form of the invention herein disclosed, it will be understood that the invention is not to be limited eX- cepting by the scope of the appended claims.

What is claimed is:

1`. The combination of a vessel having a wall formed to provide a space adapted to contain a substance, a jacket in spaced relationship to said wall to provide a vapor space between the jacket and the wall, means for generating a condensible vapor heating medium, means through which the condensible vapor is supplied to the space to heat the wall and substance in said vessel, a non-condensible gas source, means through which noncondensible gas is supplied to said space, a solenoid valve for controlling the flow of non-con densible gas to said space and adapted to ibe closed when the electrical circuit to the solenoid is open to prevent the flow of non-condensible gas to said space, non-condensible gas withdrawing means, an outlet conduit in communication with the vessel space and said gas withdrawing means, another solenoid valve, said other valve being associated with the outlet conduit and adapted to be closed when the electrical circuit to the solenoid thereof is open to prevent withdrawal of gas from said space, an electrical switch comprising spaced xed contacts, one of said contacts being in circuit with said first-mentioned solenoid valve and another of said contacts being in electrical circuit with said other solenoid valve, a movable contact cooperating with said xed contacts, and temperature responsive means for actuating the movable contact, said means being responsive to the temperature of said substance and adapted to move the movable contact into engagement with said one of the iiXed contacts and close an electrical circuit to the first-mentioned solenoid valve to thereby open the valve and permit the ow of non-condensible gas to the vessel space when the temperature of said substance rises above a predetermined degree and to move the movable contact into engagement with said other xed contact and close the electrical circuit to said other solenoid valve to thereby open the valve and permit gas to be Withdrawn from said space when the temperature 0f the substance falls below a predetermined degree.

2. The combination of a vessel having a wall -formed to provide a space adapted to contain a substance, a jacket in spaced relationship to said Wall to provide a vapor space between the jacket and the wall, means for generating a condensible vapor heating medium, means through which the condensible vapor is supplied to the space to heat the wall and substance in said vessel, a non-condensible gas source, means through which noncondensible gas is supplied to said space, noncondensible gas flow controlling means for controlling the flow of non-condensible gas to said space, non-condensible gas withdrawing means in communication with the space, non-condensible gas withdrawal controlling means for controlling the withdrawal of gas from the space, temperature responsive means associated with said vessel for controlling the actuation of the non-condensible gas flow controlling means and the gas withdrawal controlling means to regulate the flow of noncondensible gas to and the withdrawal of noncondensible gas from the vessel and thereby regulate the temperature to which the substance is heated, and non-condensible gas cut-off means associated with the vapor space and the noncondensible gas iiow controlling means to control the non-condensible gas flow controlling means so that the flow of non-condensible gas to the jacket will be cut oir when a predetermined amount of non-condensible gas is admitted to said jacket.

3. The combination of a vessel having a wall formed to provide a space adapted to contain a substance, a jacket in spaced relationship to said wall to provide a vapor space between the jacket and the wall, means for generating a condensible vapor heating medium, means through which the condensible vapor is supplied to the space to heat the wall and substance in said vessel, a non-condensible gas source, means through which noncondensible gas is supplied to said space, means for conducting non-condensible gas to said vessel vapor space, electrically operated means for controlling the flow of non-condensible gas to the vessel, non-condensible gas withdrawing means in communication with the vapor containing portion of the vessel, other electrically operated controlling means for controlling the withdrawal of non-condensible gas from the vessel, an electrical switch in circuit with the non-condensible gas withdrawal means and with the gas flow controlling means, temperature responsive means associated with the vessel and with said switch and y adapted to actuate the switch and thereby control said electrically operated and said other electrically operated means to control the non-condensible gas withdrawal controlling means and the gas flow controlling means, non-condensible gas cut-off means associated with the vessel space at a predetermined level therein and through which gas flows to the gas withdrawing means from said space, a pressure drop device in the path of ow of gas flowing from said space to the gas withdrawing means through said cut-off device, a second electrical switch in circuit with the non-condensible gas flow controlling means, and diierential pressure responsive means in communication with the path of flow of said gas from the space to the gas withdrawing means through the cut-01T device at opposite sides of the pressure drop device, said differential pressure responsive means being associated with the second electrical switch and adapted to break the circuit to the non-condensible gas flow controlling means upon an increase of pressure across the pressure drop device thereby to stop the flow of non-condensible gas to the vessel vapor space.

4. The combination of a vessel having a wall formed to provide a space adapted to contain a substance, a jacket in spaced relationship to said wall to provide a vapor space between the jacket and the wall, means for generating a condensible vapor heating medium, means through which the condensible vapor is supplied to the space to heat the wall and substance in said vessel, a non-condensible gas source, means through which noncondensible gas is supplied to said space, means for conducting non-condensible gas to said vessel vapor space, electrically operated means for controlling the ow of non-condensible gas to the vessel, non-condensible gas withdrawing means in communication with the vapor containing portion of the vessel, other electrically operated controlling means for controlling the withdrawal of said gas from the vessel, an electrical switch in circuit with the non-condensible gas withdrawal means and with the said gas flow controlling means, temperature responsive means associated with the vessel and with said switch and adapted to actuate the switch and thereby control said electrically operated and said other electrically operated means to control the noncondensible gas withdrawal controlling means and the gas flow controlling means, non-condensible gas cut-off means associated with the vessel space at a predetermined level therein and through which gas ows to the gas withdrawing means from said space, a control valve in said path'of ilow between the gas withdrawing means and the cut-off means, actuating means for the control valve comprising pressure responsive members, one of said members being in communication with and responsive to the pressure in the vessel vapor space and another of said members being in communication with and responsive to the pressure in said path of iiow between the control valve and the cut-oft means, said one member acting to move the valve toward its closed position when the pressure therein is relatively greater than in the other member, the other member acting to move the valve toward its open position as the pressure therein increases relatively to the pressure in said one member, a second electrical switch in circuit with the noncondensible gas flow 4controlling means, and differential pressure responsive means in communication with the path of flow of said gas from the space to the gas withdrawing means through the cut-off device at opposite sides of the pressure drop device, said differential pressure responsive means being associated with the second electrical switch and adapted to break the circuit to the non-condensible gas flow controlling means upon an increase of pressure across the pressure drop device thereby to stop the flow of non-condensible gas to the vessel vapor space.

5. The combination of a vessel having a wall Aformed to provide a space adapted to contain a substance, a jacket in spaced relationship to said wall to provide a vapor space between the jacket and the wall, means for generating a condensible vapor heating medium, means through which the condensible vapor is supplied to the space to heat the wall and substance in said vessel, a non-condensible gas source, a container, conduit means for conducting non-condensible gas from said source to the container, electrically actuated valve means for controlling the flow of non-condensible gas through the conduit means, a switch for controlling the flow of electrical current to said electrically actuated valve, pressure responsive means associated with said switch, said pressure responsive means comprising a member in communication with and responsive to the pressure in the means for conducting condensible vapor and another member in communication with and responsive to the pressure in the container, said one member being adapted to actuate the switch so as to close the electrical circuit to the valve means and cause the same to open when the pressure in said one member is relatively greater than in said other member, the other member being adapted to actuate the switch so as to open the circuit to the valve means and permit the same to return to its normally closed position when the pressure in said other member is relatively greater than in said one member, means through which non-condensible gas is supplied to said space, means for withdrawing non-condensible gas from the space, and means for regulating the amount of condensible vapor used in said space by controlling the amount of non-condensible gas supplied to and withdrawn from said space to thereby control the temperature to which the substance in the vessel is heated.

6. The combination of a vessel having a wall formed to provide a space adapted to contain a substance, a jacket in spaced relationship to said wall to provide a vapor space between the jacket and the wall, means for generating a condensible vapor heating medium, conduit means in communication with the supper part of the vessel vapor space and with the condensible vapor generating means, a, non-condensible gas source, a conduit for conducting non-condensible gas from said source to the lower part of the vessel vapor space, electrically operated means for controlling the iiow of non-condensible gas to the vessel, noncondensible gas withdrawing means in communication with the vapor containing portion of the vessel, other electrically operated controlling means for controlling the withdrawal of said gas from the vessel, an electrical switch in circuit with the non-condensible gas withdrawal means and with said gas iiow controlling means, temperature responsive means associated with the vessel and with said switch and adapted to actuate the switch and thereby control said electrically operated and said other electrically operated means to control the non-condensible gas withdrawal controlling means and the gas flow controlling means, non-condensible gas cut-oir means associated with the upper part of the vessel vapor space at a predetermined level therein and through which gas flows to the vapor withdrawing means from said space, a pressure drop device in the path of now of gas owing from said space to the gas withdrawing means through said cut-oli device, a second electrical switch in circuit with the non-condensible gas flow controlling means, and differential pressure responsive means in communication with the path of flow of said gas from the space to said gas withdrawing means through the cut-oir device at opposite sides of the pressure drop device, said differential pressure responsive means being associated with the second electrical switch and adapted to break the circuit to the non-condensible gas flow controlling means upon an increase of pressure across the pressure drop device thereby to stop the flow of non-condensiole gas to the vessel vapor space.

7. The combination of a vessel having a wall formed to provide a space adapted to contain a substance, a jacket in spaced relationship to said wall to provide a vapor space between the jacket and the wall, means for generating a condensible vapor heating l edium, conduit means in communication with the lower part of the vessel vapor space and with the condensible vapor generating means, a non-condensible gas source, a conduit for conducting non-condensible gas from said source to the upper part of the vessel vapor space, electrically operated means for controlling the flow of non-condensible gas to the Vessel, non-condensible gasA withdrawing means in communication with the vapor containing portion of the vessel, other electrically operated controlling means for controlling the withdrawal of gas from the vessel, an electrical switch in circuit with the non-condensible gas withdrawal means and with the gas iiow controlling means, temperature responsive means associated with the vessel and with said switch and adapted to actuate the switch and thereby control said electrically operated and said other electrically operated means to control the non-condensible gas withdrawal controlling means and the gas iiow controlling means, non-condensible gas cut-01T means associated with the lower part of the vessel vapor space at a predetermined level therein and through which said gas flows to the vapor withdrawing means from said space, a pressure drop device in the path oi iiow of gas flowing from said space to the gas withdrawing means through said cut-off device, a second electrical switch in circuit with the no-n-condensible gas flow controlling means, and diierential pressure responsive means in cdmmunication with the path of iiow of said gas from the space to the gas withdrawing means through the cut-off device at opposite sides of the pressure drop device, said differential pressure responsive means being associated with the second electrical switch and adapted to break the circuit to the noncondensible gas flow controlling means upon an increase of pressure across the pressure drop device thereby to stop the ilow of non-condensible gas to the vessel vapor space.

8. The combination of a plurality of vessels each having a wall formed to provide a space adapted to contain a substance, a jacket in spaced relationship to said wall to provide a vapor space between the jacket and the wall, means for generating a condensible vapor heating medium, means through which the condensible vapor is supplied to the space to heat the wall and substance in each vessel, a non-condensible gas source, means through which non-co-ndensible gas is supplied to the vapor space of each Vessel, means for withdrawing non-condensible gas from the vapor space of each vessel, electrically operated means associated with each vessel for controlling the flow or non-condensible gas to the vessel, gas withdrawing means, an outlet conduit in communication with the vapor space of each vessel and the gas withdrawing means, other electrically operated controlling means associated with the outlet conduit of each vessel for controlling the withdrawal of gas from the vessel, an electrical switch associated with each vessel and in circuit with the non-condensible gas withdrawal means and with the gas iiow controlling means, temperature responsive means associated with each vessel and with said switch and adapted to actuate the switch and thereby control said elec rically operated and said other electrically operated means to controithe noncondensible` gas withdrawal controlling means and said gas flow controlling means, non-condensible gas cut-off means associated with each vessel space at a predetermined level therein and through which gas ows to said gas withdrawing means from said space, a pressure drop device in the path of ilow of gas flowing from each space to said gas withdrawing means through said cut-ofi device, a second electrical switch associated with each vessel and in circuit with the noncondensible gas flow controlling means, and differential pressure responsive means in communication with the path of flow of said gas from the space of each vessel to the gas withdrawing 15 means through the cut-off device at opposite sides of the pressure drop device, said diferential pressure responsive means being associated with the second electrical switch and adapted to break the circuit to the non-condensible gas flow controlling means upon an increase of pressure across the pressure drop device thereby to stop the flow of non-condensible gas to the vessel vapor space.

9. The combination of a vessel having a wall formed to provide a space adapted to contain a substance, a jacket in spaced relationship to said wall to provide a vapor space between the jacket and the wall, means for generating a condensible vapor heating medium, means through which the condensible vapor is supplied to the space to heat the wall and substance in said vessel, a noncondensible gas source, means through which noncondensible gas is supplied to isaid space, means for conducting non-condensible gas to said vessel vapor space, electrically operated means for controlling the flow of non-condensible gas to the vessel, non-condensible gas withdrawing means in communication with the vapor containing portion of the vessel, other electrically operated controlling means for controlling the withdrawal of gas from the vessel, an electrical switch in circuit with the non-condensible gas withdrawal means and with said gas ow controlling means, temperature responsive means associated with the vessel and with said switch and adapted to actuate the switch and thereby control said electrically operatedand said other electrically operated means to control the non-condensible gas withdrawal controlling means and the vapor new controlling means, non-condensible gas cut-oiic means associated with the vessel space at a predetermined level therein and through which gas flows to said gas withdrawing means from said space, said cut-off device comprising a condenser for condensing condensible vapor, a condensate return conduit communicating with the condenser and the vessel vapor space, a second condensate return conduit communicating with said vapor space and the condensible vapor generating means, a pressure drop device in the path ci flow of gas flowing from said space to the gas withdrawing means through said cut-oil device, a second electrical switch in circuit with the noncondensible gas 'flow controlling means, and differential pressure responsive means in communication with the path of flow of said gas from the space to the gas withdrawing means through the cut-off device at opposite sides of the pressure drop device, said differential pressure responsive means being associated with the second electrical switch and adapted to break the circuit to the non-condensible gas ow controlling means upon an increase of pressure across the pressure drop device thereby to stop the flow of non-condensible gas to the vessel vapor space.

10. The combination of a vessel having a substance containing portion adapted to receive a substance to be heated, vapor receiving means in heat exchange relationship with substance in said substance containing portion, means for generating a condensible vapor heating medium, means through which the condensible vapor is supplied to the Vapor receiving means, a noncondensible gas source, means through which non-condensible gas is supplied to the vapor receiving means, means for withdrawing non-condensibles from said vapor receiving means, and means for regulating the amount of condensible vapor used in the vapor receiving means by controlling the amount of non-condensible gas sup- 16 plied to and withdrawn from said receiving means to thereby control the temperature to which the substance in the vessel is heated.

11. The combination of a vessel having a substance containing portion adapted to receive a substance to be heated, vapor receiving means in heat exchange relationship with substance in said substance containing portion, means for generating a condensible vapor heating medium, means through which the con-densible vapor is supplied to the vapor receiving means, a non-condensible gas source, means through which non-condensible ygas is supplied to the vapor receiving means, means for withdrawing non-condensibles from said vapor receiving means, and means responsive to the temperature of the substance in the vessel for regulating the amount of condensible vaporv used in the vapor receiving means by regulating the amount cf non-condensible gas supplied to and withdrawn from the receiving means.

12. The combination of a vessel having a substance containing portion adapted to receive a substance to be heated, vapor receiving means in heat exchange relationship with substance in said substance containing portion, means for generating a condensible vapor heating medium, means through which the condensible vapor is supplied to the vapor receiving means, a non-condensible gas source, means through which non-condensible gas is supplied to the vapor receiving means, means for withdrawing non-condensibles from said vapor receiving means, means for limiting the amount of non-condensible gas admitted to the vapor receiving means, means for withdrawing non-condensible gas from said receiving means, and means responsive to the temperature of the substance in the vessel for regulating the amount of condensible vapor used in the vapor receiving means by regulating the amount of non-condensible gas supplied to and withdrawn from said receiving means.

13. The combination of a vessel having a substance containing portion adapted to receive a substance to be heated, vapor receiving means in heat exchange relationship with substance in said substance containing portion, means for generating a condensible vapor heating medium, means through which the condensible vapor is supplied to the vapor receiving means, a non-condensible gas source, means .through which non-condensible gas is supplied to the vapor receiving means, means for withdrawing non-condensibles from said vapor receiving means, and means responsive to the temperature of the substance in the vessel for regulating the amount of condensible vapor used in the vapor receiving means by regulating the amount of non-condensible gas supplied to and withdrawn from said receiving means .to maintain constant the temperature to which said substance is heated.

DION K. DEAN:

REFERENCES CITED The following references are of record in the iile of this patent:

UNITED STATES PATENTS Number Name Date 1,056,143 Armstrong Mar. 18, 1913 680,471 Armstrong Aug. 13, 1901 2,220,584 Seeley Nov. 5, 1940 2,323,849 Schnoes July 6, 1943 645,929 Osborne Mar. 20, 1900 2,317,480 Peters Apr, 27, 1943 1,930,213 Smalle Oct. 10, 1933 Certicate of Correction Patent No. 2,432,985. December 23, 1947.

DION K. DEAN It is hereby certified that errors appear in the printed specification of the above numbered patent requiring` correction as follows:

Column 6, line 39, for thereo read thereto; column 8, line 16, for plate 88" read plate 86' column 9, line2`, for coil 11 read coil 111 lines 35 and 48, for packet read jacket; column 13, line 21, for supper read upper; line 44, for vapor read gas; and that the said Letters Patent should be read With these corrections therein that the same may conform tothe record of the case in the Patent Oce.

Signed and sealfellgthis 14th day of December, A. D. 1948.

THOMAS F. MURPHY,

Assistant 'ommz'ssoner of Patents. 

